Technical Field
This disclosure relates to a flexible circuit board inspecting apparatus for inspecting a flexible circuit board.
Related Art
Heretofore, circuit board inspecting apparatuses have been proposed for inspecting a circuit pattern formed on a circuit board. Japanese Patent No. 5,179,289 discloses such a circuit board inspecting apparatus.
The circuit board inspecting apparatus disclosed in Japanese Patent No. 5,179,289 includes a circuit board fixing device for fixing a circuit board, and a probing device for probing the circuit board. The circuit board fixing device includes a clamp mechanism capable of clamping an edge of the circuit board. The probing device includes probe units each capable of bringing a probe pin into contact with a conductor pattern on the circuit board. The probe units are disposed in correspondence with front and back surfaces of the circuit board, respectively.
According to this configuration, the circuit board fixing device clamps the circuit board oriented horizontally, and the probe pins come into contact with both the surfaces of the circuit board from above and below, respectively. The probe units apply electric signals to the circuit board to conduct a predetermined electrical inspection on the circuit board.
The circuit board inspecting apparatus disclosed in Japanese Patent No. 5,179,289 is dedicated to the purpose of inspecting a so-called rigid circuit board which is a circuit board having a certain degree of hardness. Recently, on the other hand, circuit boards with flexibility (hereinafter, simply referred to as “flexible circuit boards”) have been occasionally used for the purpose of reduction in thickness, improvement in electrical characteristic, and the like. For example, a large number of touch panels is collectively fabricated in the form of an elongated film-like multiple circuit board, and then a roll of the elongated film-like multiple circuit board is supplied to a subsequent process. Therefore, such a flexible circuit board brings about excellent advantages such as a cost reduction by mass production and an improved handleability.
This flexible circuit board brings about the advantages described above, but tends to be easily warped or bent. Therefore, this flexible circuit board is required to be handled with care. In this respect, the circuit board inspecting apparatus disclosed in Japanese Patent No. 5,179,289 is configured to inspect a circuit board by holding the circuit board from above and below with the probing device while clamping the circuit board oriented horizontally. Accordingly, if the circuit board inspecting apparatus disclosed in Japanese Patent No. 5,179,289 is used for inspecting the flexible circuit board, the flexible circuit board tends to be bowed downward under its own weight. Consequently, it is difficult to bring the probe pin into contact with an accurate position on the flexible circuit board. Particularly, it is considerably difficult to simultaneously inspect both surfaces of the flexible circuit board.
In the case where the circuit board inspecting apparatus disclosed in Japanese Patent No. 5,179,289 is used for inspecting the flexible circuit board, moreover, when the probe pin is brought into contact with the flexible circuit board from above, the flexible circuit board is applied with its own weight and a downward pressing force by the probe pin. Therefore, the flexible circuit board tends to be further bent. In order to prevent the flexible circuit board from being bent in such a case, a clamping device is employed for clamping the flexible circuit board more firmly. However, the use of the clamping device is not preferable since the clamping device increases in size, complexity, and weight.
In addition, the circuit board inspecting apparatus disclosed in Japanese Patent No. 5,179,289 moves the probe pin in an upward direction and a downward direction to bring and separate the probe pin into contact with and from the circuit board. Accordingly, the circuit board inspecting apparatus requires large drive means in order to lift up the heavy probe unit and a member for supporting the probe unit against gravity, so that this drive means causes an increase in cost.